Four or five years ago I was told that I should place a rifle reload like that as I did not have any other place to put one. I asked if I could stage it on the table and was told NO, I no longer shoot at that club. first time I was ever told I could not stage ammo on the table.
kR
When a cartridge is fired the primer backs out then the case is pushed back and reseats the primer. If you don't believe me just put any case in any gun with just a primer and fire it . The primer backs out and because there is no pressure to push the case back the primer will be sticking out slightly. Same thing occurs when loads are to light. How many times have you told someone to use more powder their load is to light?
kR
You should not have to change the primer pocket to go from large rifle to large pistol, just make sure the primer is seated all the way. The large rifle primers are higher than the large pistol primers so you can not use large rifle as a substitute in large pistol brass.
kR